This invention relates to a fuel pump arrangement for an engine and particularly to an improved fuel pump drive arrangement that can be utilized with a four-cycle outboard motor.
The charge forming systems for internal combustion engines normally employ a one or more fuel pumps for pumping fuel to the charge formers of the engine. This is true regardless of whether the charge former is a carburetor or a fuel injector. Although a wide variety of types of fuel pumps and fuel pump drivers are employed. One conventional type of system used with four cycle engines employs a fuel pump that is driven from the camshaft of the engine. Normally, the fuel pump is driven off of an end of the camshaft through a drive coupling. This type of arrangement has a number of disadvantageous.
First, the utilization of the drive coupling provides a mechanical connection which can complicate other servicing of the engine. For example, if the drive coupling is positioned adjacent the camshaft drive mechanism, then the setting of the timing of the camshaft may become difficult.
In addition to the basic drive problems, the location of the drive for the fuel pump off of an end of the camshaft generally dictates that the fuel pump is disposed at one end or the other of the engine. This does not permit the optimization of the location of the fuel pump to the components to which it supplies fuel. That is, if there is provided a fuel injector or carburetor for each cylinder, then the fuel pump may positioned at a substantially greater distance from one charge former than the others.
Finally, this end positioning of the fuel pump tends to add to the overall length of the engine. This is particularly disadvantageous when the engine is employed in conjunction with an outboard motor. As is well known, outboard motors have very compact construction and there is not a lot of space available between the external periphery of the engine of the outboard motor and its surrounding protective cowling.
It is, therefore, a principal object of this invention to provide an improved and compact fuel pump and drive arrangement for an internal combustion engine.
It is a further object of this invention to provide an improved and compact drive for the fuel pump of an outboard motor.
It is a still further object of this invention to provide an improved and compact drive arrangement for driving a fuel pump of an engine from the engine camshaft.
It is a still further object of this invention to provide an improved fuel pump drive arrangement for an internal combustion engine wherein a greater latitude is possible in the positioning of the fuel pump due to the manner in which it is driven.